How Katherine Waterston Got In Shape to Kick Some Serious Butt In Alien: Covenant

In the latest installment of the Alien franchise, set 10 years after 2012�s Prometheus,�a�new heroine has been charged with kicking some major alien butt:�Katherine Waterston plays�Daniels, a chief teraformist on a colonizing mission to a new planet. And after an advanced screening of Alien: Covenant, which hits theaters Friday, I can assure you that Waterston embodies the�strong female lead that’s�been a staple of�the Alien movies since Sigourney Weaver�s portrayal of Ellen Ripley, the original badass known for beating down extraterrestrials.

As you might�imagine, sparring with (or running from!) blood thirsty�and let’s face it, pretty freaking scary�creatures isn�t an easy task. Translation: Waterston needed to be in great shape.

�I was so nervous that [director] Ridley [Scott] wasn�t going to let me do the stunts,” she said during a pre-screening talkback with cast members. “There was a sort of fit test at the beginning that nearly killed me, but I didn�t want to seem like I couldn�t handle it, because I thought they might take the fun moves away from me.”

But the 37-year-old actress explained that she didn’t arrive on set in the best shape of her life on purpose:�”I didn�t want to seem like some kind of warrior at the beginning of the film, because I feel like that journey happens within it, so I didn�t want to come in too ripped,” she said.

Waterston’s plan worked: She got progressively fitter just by playing her role, she said. “A lot of the training happened on set because we were carrying heavy packs and carrying really heavy guns�for me it was heavy.”

Still, Waterston�knew she needed to build muscle before�filming began�to avoid getting hurt on the job. “I didn�t want to rip my shoulder out my socket or something,” she said.

RELATED: 11 Best Exercises to Get Strong, Toned Arms

One of her�strengtheners�of choice: �curls, really heavy bicep curls.” Which totally makes since considering you�ll see her wielding gigantic guns, and swinging and climbing around a space shuttle for two-plus hours.

Channel your inner warrior and try a few: Stand tall with feet hip-width distance apart and arms at sides, a dumbbell in each hand; palms face forward. Without moving upper arms, bend elbows and curl�weight toward shoulders. Slowly lower back to start, and then repeat.

Prefer to do curls with a cable machine? Check out the video below to see the proper form.

Clearly Waterston nailed her training approach for the sci-fi horror flick because actor Michael Fassbender (who plays the androids�David and Walter�in the film)�had this to say about his costar: �She was fearless.�